The new 1.5 installer puts two files in the LC\Scenery folder, toronto_lc.offandtoronto_lc.bgl. As a result trying to disable LC from the configurator results in it crashing. Removing the .off one rectifies the issue.

Checked... installer forgets to wipe the old install's _LC folder. So the new version copies toronto_lc.bgl in there, overwriting the existing BGL, but if there was a .OFF file it will be left in place and can/should be manually deleted.